(1. 大连理工大学 汽车工程学院，大连 116024；
2. 大连理工大学 工程力学系，大连 116024；
3. 吉林大学 材料科学与工程学院，长春 130022)
摘 要: 基于GTN损伤模型，采用实验与有限元仿真相结合的方式对高强度7075-T6铝合金在温成形HFQ工艺过程中的损伤演化进行研究。通过扫描电镜观测得铝合金板材在变形中的损伤演化符合孔洞长大、形核、聚合和最终断裂的规律；采用中心复合试验设计法构造拉伸曲线关键变量关于GTN损伤参数的响应曲面模型，进而结合遗传算法确定铝合金板材的损伤参数；通过有限元软件ABAQUS仿真预测不同温度下铝合金方盒拉深过程中的损伤分布情况。结果表明:提高成形温度可使得铝合金板材的成形性得到有效改善，实验观测的板材开裂行为和开裂位置与损伤预测结果相一致，证明了GTN损伤模型在铝合金温冲压成形性仿真分析中的适用性。
关键字: 7075-T6铝合金；温成形；GTN损伤模型；损伤识别；数值模拟
（1. School of Automotive Engineering, Dalian University of Technology, Dalian 116024, China;
2. Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China;
3. College of Materials Science and Engineering, Jilin University, Changchun 130022, China）
Abstract:Based on GTN damage model, both experimental and FEM method were used to research the damage evolution of high strength 7075-T6 aluminum alloy during warm forming HFQ process. Through the microstructure observation, the damage evolution within tested material corresponds to the process of void growth, nucleation, coalescence and subsequent fracture. The response surface model between GTN parameters and critical points of tensile curve was built based on central composite design. Then, the genetic algorithm was adopted to determine damage parameters of this aluminum alloy. After that, damage distribution during square cup deep-drawing process was predicted by finite element software ABAQUS. The results show that the formability of aluminum alloy can be improved significantly with the temperature increasing. The fracture behavior and location obtained by experiment consist with those by prediction. So, it demonstrates the applicability of GTN damage model in analyzing formability of aluminum alloy during warm forming.
Key words: 7075-T6 aluminum alloy; warm forming; GTN damage model; damage identification; numerical simulation
